Control moment gyroscopes have been in use for many years in both single gimbal and double gimbal versions to control the attitude of spacecraft. The single gimbal control moment gyroscope is advantageous over the double gimbal control moment gyroscope in that the useful output torque applied to the spacecraft by the single gimbal control moment gyroscope can be orders of magnitude greater than the torque applied by the torque motor. The high output torque capability of the single gimbal control moment gyroscope results from the fact that the torque applied from the torque motor in the single gimbal control moment gyroscope design need overcome only the static inertia of the spin wheel to cause the gyroscope to precess.
In contrast to the single gimbal control moment gyroscope, a conventional double gimbal control moment gyroscope provides no torque magnification over that supplied by the torque motor. The conventional double gimbal control moment gyroscope disadvantageously requires impracticality large torque motors to provide high torque control. Thus, a desirable feature of the single gimbal control moment gyroscope design over that of the conventional double gimbal control moment gyroscope is that small torque motors can be used to create large control torques. However, the single gimbal control moment gyroscope system disadvantageously requires two separate devices to provide high torque control along two axes while the conventional double gimbal control moment gyroscope design requires only a single large torque motor. Accordingly, the current design approach to meet high torque control requirements in gyroscope systems uses a multiplicity of single gimbal control moment gyroscopes. Thus, an approach is sought which combines the high torque capabilities of the single gimbal control moment gyroscope with the dual-axis control of the double gimbal control moment gyroscope.